High-frequency signaling system



April 28, 1931.

E. AUSTIN 1,803,161 HIGH FREQUENCY SIGNALING SYSTEM Filed April 18, 1922 l 1 6 b V I I I I 8 li y 1 1 9 AVAI"".

3/ L V Y w sooner: o

ouRRENT L TEIIKSMITTEI? 5 lllllll Inventor:

Edward Ausi h'w His Attorfies.

are conducted overwires.

Patented Apr. 28, 1931 ewe STATES PATENT OFFICE E WARD aus'rm, or scnnnnomny, NEVT YORK; ASSIGNOR TO GENERAL COMPANY, A CORPORATION OF NEW YORK nLncTnIc HIGH-FREQUENCY SIGNALING- SYSTEM Application filed April is,

My presentinvention relates to signaling systems and more particularly to signaling systems of the so-called carrier current type in which high frequency signaling currents The object of my invention is to provide a signaling system in which connections employed for distributing powermay also be employed for signaling .by means of carrier currents and receiving devices for the signaling currents may beaconnected to the distribution system in the same way that any current'consuming device such as an incandescent lamp is connected thereto. V Onetypical case in .which my invention may be employed to advantage is that ofa secondary distribution system for supplying electric current for lightingrorpower'purposesto individual consumers. 7 Such asystein usually comprises a central station from which, current isdistributed through a pluralityof feeder. circuits to an entire community In's'uch'a case ,I inayimpress the high frequency signaling currents upon the bus bars of the central station and they will bedistributed throughout the entire distribution system. Any! consumer ofcurrent for lighting or power purposes who is provided with a suitable receiving apparatus may then connect his receiving apparatus to "a lamp socket or other outlet in the house'wiring sys- :-tem andreceive-the signals sent out over the system. Thesystem is particularly adapted for the broadcasting ofnews or music,'etc., as any number of -customers ofthe power system may simultaneously receive the signals trans mitted. It is not however limited in its usefulness to this particular application as by "suitable modification in' the receiving; apparatus and .by the provision of suitablecalling apparatus any individual consumer may 'bejcalled'as inan ordinary telephone systemand communication may be had between any a two customers'of the power system without 922. Serial no; 555,376.

interfering with. the use offthe system by other individuals at the same time. V

The novel features which I believe to be characteristic of my invention are set forth withparticularity in theappendedclaims. My invention itself, however, both as to its organization and method of'operation will best be understood by reference to the following description taken'in connection with the accompanying drawing in which -I have shown diagrammatically oneway whereby my invention may be carried into efi'ect.

I have indicated in the drawing a central power station lfin whichasource of current a 2 supplies current to the bus bars 3, 4. From these bus bars current'is supplied to the feeder 'circuits5 6 and 7. The potential of these feeder circuits will ordinarily be'fairly high and' current will be suppliedto wiring systemslin buildings through stepdownf transf formers'8; 9fan'd 10. Current from the sec- ;ondaries' offthese transformers will be supplied to a pluralityof current consumption devices" 11, "such as incandescent lamps, motors, heating devices, etc. v

" In the present caseI have indicated afsig-,

-nal transmitter 12 connectedto the bus bars 8 and 4 through condensers 13, of comparatively low capacitywhich.prevent the flow of current from the" power distribution' system a inthe signal transmitting apparatus. The

transmitter 12 may be of any form suitable connected by means of a plug 14 toany socket 15 in place of a lainpor other current consuming device. The receiving (311'011111 connected to the plug 14: may include. .a filter circuit made up of condensers: 16. and inductances 17 a for preventing the normal current in'the distribution system from affectingthe receiving apparatus which I have illustrated as being 7 of the, usual vacuum tube typewith an indicating device'18,which may be a loud speaking telephone, in the plate circuit. It will of course be understood that any form of detecting and amplifying apparatus which is employed with high frequency signaling ourrents transmitted over grounded circuits or through the ether,-may be'e'mployed in producing an indication of currents transmitted in the manner which I have described. It may be desirable in some cases to prevent the signaling current from being distributed over the entire distribution system.- Feeder G, for example, may supply'current for street lighting purposes only and any signaling current sent over this feeder would be entirely lost. In such a case chokecoils 19 may be inserted in the feeder to prevent the high frequency current from flowing in that portion of the distribution system.

What I claim as new anddesireto-secure by Letters Patent of the United States, is 1. A combined power and broadcasting system comprising in combinationia source of alternating power current having f a? low frequency, a power transformer having one winding connected across said source'of alternating current power, a powerconsumptioncircuit connectedlacross a second winding of said transformer, means for supplying a high frequency carrier electromotive force to the first winding in parallel'with the electromotive force ofsaid source of, alternating current power; said carrier electromotive force having a frequency materially higher than the, usual voice frequencies, means for modulating said carrier electromotive force with currents of'voice' frequency, andQaCarrier current receiver connectedacross the second of said transformer windingsthrough a :quency, a power transformer V aving one to ternatiug power current,.a power consumption circuit connected across a secondwindin'g winding connected across said source of aloffsaid. transformer, means for supplying-a 5 force of said v source I of alternating current power, means for modulating said broadcastiblroadcastingl carrier wavef frequency electro- -motive force in parallel with the electromotive ":ing carrier wave frequency electromotive force with currents of voice frequency, and

a broadcast receiver coupledacross said second winding of said transformer through a coupling means which is effective for transmitting currents of said carrier frequency but substantially ineffective in transmitting currents of the power frequency, said -re-' ceiver being adapted to detect and reproduce said voice frequencies.

3. A system of distribution comprising a relatively high voltage low frequency power feed circuit and a lower potential power consumption circuit, a power transformer, said transformer having one winding'connected across two conductors of said feed circuit and a second winding connected'to said lower po-. tential circuit, means for impressing modulatedghigh frequency signaling electromotive forces across said two conductors 'of said feed circuit, said means comprislng coupling means for said high frequency signalingelec.

, tromotive forces offering extremely high impedance for currents of the power frequency, a plurality 'of-current consumption devices operable at said low frequency and connected to said lower potential circuit, and a receiver adapted to detect and; reproduce said modulations, said receiver beingconnected to said lower potentialcircuit in place of one of'said current consumption devices and in 1 parallel with other current consumption devices through coupling means which is effectivefor the signaling frequency but which offers an "extremely highimpedanceto currents of the power frequency.

4. A system of distribution comprising a relativelyhigh voltage low frequency power feed circuit and a lower potential power consumption circuit connected to said feed circuit through a distribution transformer, means for impressing modulated'high frequencjy signalingelectromotive. forces across two conductors ofsaid feed circuit, said electromotive forces bein impressed in parallel 'withthe relatively hi'gh voltage applied to said feed circuit a plurality of current consumptiondevices operable at saidlow fre- "quency and connected tosaid lower potential circuit, a receiver ada ted to be connected to sald lower potentialclrcuit in place of. onerof said current consumption dev ces and n. parallel with other current consumption devices for receivin said modulated high frequency ios flo

currents an producingan audible indication,

and means for excluding power currents from said receiver.

'5. The combination in a signaling system .of an alternating current power distribution system for. distributing energy to electric lamps or other currentconsuming devices comprising acentral powerstation, a plue rality of feederci'rcuits of comparatively high voltage connected tobus barsin'said power distribution system,-a plurality of lowerpotential circuits connected to said feeder circuits through transformers and having current consumption devices connected thereto,

said transformers each comprising two. in-

ductively related w1nd1ngs,one of said windings comprising a portion ofone of said lower potential circuits, the other of said windi eing connected across one of said feeder cucuits, means for impressing broadcast frequency signaling electromotive forces upon said bus bars in parallel with the power electromotive force supplied to said bus bars, 

